The present embodiments relate to an intermediate network in a ring topology.
Ethernet-network domains may be connected to one another via virtual Ethernet connections via an intermediate network in order to facilitate network traffic between otherwise disjoint network domains. For example, in industrial applications (e.g., in factory or process automation), the requirements for reliability and failsafe operation of such Ethernet links are very high in order to provide the security of the networked components.
These Ethernet connections between network domains may be implemented via virtual private networks (VPN) (e.g., a virtual private wire service (VPWS) or a specially preconfigured virtual local network (VLAN)). These virtual private network connections are established via an intermediate network, the operation of which may be outside the sphere of influence of the network domain operator.
Network traffic between two network domains connected via such an intermediate network with the help of virtual private network connections may be controlled such that there are no unwanted data traffic loops. Network security is to be established in the network traffic between the network domains, which may capture failures of network components in the intermediate network without being dependent upon the security measures of the intermediate network operator.
The two network domains may, for example, be integrated into a joint network with cross-domain redundancy protocols such as RSTP, for example. However, this requires a high implementation cost. This also requires a large amount of planning in order to keep network-domain-internal network traffic inside the domain (e.g., to prevent network traffic that is supposed to take place within a domain from being routed via the intermediate network, thus causing unnecessary costs and latencies).
Alternatively, proprietary protocols that permit additional information to be exchanged via individual connections between the network domains and thus to respond to any faults that may occur may be used. This solution, however, lacks flexibility and requires a high level of adaptation to the existing infrastructure.